To provide a rotating anode type X-ray tube that prevents leakage of liquid metal lubricant and stably supplies a just enough quantity of the liquid metal lubricant to a dynamic-pressure sliding bearing during operation, and a manufacturing method thereof.

The rotating anode type X-ray tube comprises an anode target 12, a rotary mechanism 15 having an inner cylinder 17 and a stator 19 with the dynamic-pressure sliding bearings 23 and 24 in between and supporting the anode target 12 rotatably, and a vacuum vessel 11 accommodating the anode target 12 and the rotary mechanism 15. Between the dynamic-pressure sliding bearings 23 and 24 and a space in the vacuum vessel 11, a dynamic pressure generating part 36 is disposed on the stator to generate pressure on the liquid metal lubricant and in the direction of the dynamic-pressure sliding bearings 23 and 24.